It has become common in recent years to install monitoring cameras in railway vehicles to record crimes, incidents, and accidents that occur in the vehicles. There are generally three methods of checking images from the monitoring cameras.
A first checking method is to check images taken by a monitoring camera on a real-time basis by the driver or conductor via a display unit installed in the cab for checking the safety in the vehicles. This checking method is used, for example, to make sure that no object is caught in the vehicle doors or no passenger is caught in the vehicle doors, before leaving the station. A second checking method is to display image data of the images taken by a monitoring camera when a vehicle is operating on a display unit in the cab, or continuously record the image data in a recording device and, if an incident or accident occurs, use the recorded image data to check images during the period of time when the incident or the like occurs. With these two checking methods, because the images taken by the monitoring camera are displayed on the display unit in the cab, when an incident or the like occurs, the driver or the like checks the images displayed on the display unit.
A third checking method is such that when an emergency call device in a vehicle is operated, images from a monitoring camera that is taking images of the vicinity of the emergency call device are displayed on a display unit in the cab. For example, when the emergency call device is operated by a passenger when an incident or the like has occurred, the conductor or the like needs to rush to the place of the incident immediately. However, the conductor or the like may wish to check the images taken by the monitoring camera in order to quickly check the status. The third checking method is suitable for such a case. A method that can be considered, other than the method described above, for quickly checking the status when the emergency call device is operated is a method by which the vehicle and the operations room are connected via a network in order for a supervisor in the operations room to ascertain the current status.
As a monitoring operating system that can accurately recognize an incident or the like in the monitoring area, the conventional technique described in Patent Literature 1 mentioned below provides a system in which a plurality of monitoring poles are installed on the platforms or the like in the station. According to the conventional technique, when an emergency notification unit attached to the monitoring pole is operated, monitoring cameras built in other poles arranged near the operated pole is controlled such that they concentrate on taking images near the operated pole. The respective monitoring poles and an emergency operating system are connected to the monitoring control unit via a LAN.
The conventional technique described in Patent Literature 2 mentioned below provides a system in which a plurality of imaging units each including a camera, a display unit, and an emergency push button are installed in a railway vehicle, and when an abnormal situation occurs, images taken by the camera of the imaging unit whose emergency push button has been pressed are displayed on a display device in the driver's cabin.